Her's the instructions copied from the service manual:
Starter Motor Removal
1. Remove the seat, left side panel, and disconnect the battery.
2. Remove the (+) positive wire (A) from the starter motor terminal.
3. Remove the upper starter motor fastener (1) securing the starter motor and (-) negative battery cable to the engine. Completely loosen the lower starter motor fastener.
NOTE: The (-) negative battery cable is mounted to the the engine using the upper starter mounting bolt.
4. Remove the starter from the engine.
Pics of your dilemma might help.
I personally have not changed a starter motor on a 570, so I am not familiar with the problem you have encountered.
Shop Owner and Mechanic with over 50 years experience